docs: def date2juldate(val):
      '''Convert from a python date/datetime to a Julian date & time'''
      f = 12*val.year + val.month - 22803
      fq = f // 12
      fr = f % 12
      dt = (fr*153 + 302)//5 + val.day + fq*1461//4
      if isinstance(val, datetime):
          return dt + (val.hour + (val.minute + (
              val.second + 0.000001*val.microsecond)/60.)/60.)/24.
      else:
          return dt